Jack construction



Sept. 9, 1969 as. HEWES, JR.. ETAL 3,466,011

JACK CONSTRUCTION Filed May 26, 19s? 2 Sheets-Sheet 1 Fig.2

George 8. Halves, Jr.

James Leon Conner I N VENTOR$ p 1969 e. B. HEWES, JR., EI'AL 3,466,011

JACK CONSTRUCTION Filed May 26, 1967 2 SheetsSheet 2 Fig 3 I I o o 4 \Q -1 I 38 I8 1 1; I2

George B. Hewes. Jr.

James Leon Conner INVENTORS m3. /04 MM United States Patent M Int. Cl. B66f 3/16 US. Cl. 254-97 Claims ABSTRACT OF THE DISCLOSURE A jack construction for use on a shelter unit for supporting the shelter unit in a level condition and at a desired elevational position. The shelter unit is provided with a jack construction at each corner thereof with a bracket or adapter attached to the shelter unit and provided with a tubular sleeve slidably receiving an elongated cylindrical member having a rack gear extending substantially throughout the length thereof. A manually operated pinion gear is mounted on the bracket or adapter in meshing engagement With the rack gear for lowering and raising the elongated cylindrical lift member in relation to the shelter unit. The bracket or adapter and the elongated cylindrical lift member are provided with bearing members therebetween in such a manner to facilitate movement of the elongated cylindrical lift member without scufling, galling or the like of the elongated cylindrical lift member and the sleeve forming part of the bracket or adapter. A self-levelling foot is attached to the lower end of the elongated lift member for universal pivotal movement thereof for enabling the supporting surface to be fully engaged by the foot even though the supporting surface may be inclined or irregular.

The present invention generally relates to a jack construction primarily constructed for use at each corner of the portable shelter unit for supporting the shelter unit in a level condition and in an adjustable elevated position which includes a bracket attached to the shelter unit and having a sleeve therein slidably receiving an elongated lift member provided with a rack gear thereon. A drive pinion connected to an operating ratchet handle through a worm gear arrangement is mounted on the bracket and engages the rack gear for raising and lowering the lift member. The sliding engagement between the elongated lift member and the bracket is provided with insert bearing forming surfaces which are non-metallic in nature and are self-lubricated and preferably constructed of a plastic material. The lower end of the elongated lift member is provided with a self-levelling foot universally attached thereto in a manner which securely retains the foot in place but enables limited rocking movement thereof.

An object of the present invention is to provide a jack construction having a novel sliding interconnection between the lift member and the sleeve-type bracket together with a novel self-levelling foot at the lower end of the lift member and structural features which enable the device to be easily attached to a shelter unit and also enabling easy operation thereof with the operation of the device being efficient and long lasting Without requiring application of lubricating materials to the relative moving parts.

Still another object of the present invention is to provide a jack construction which is simple in construction, easy to use, long lasting and dependable and relatively inexpensive to manufacture.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter 3,466,011 Patented Sept. 9, 1969 ice described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of one corner of a shelter unit illustrating the jack construction constituting the present invention attached thereto;

FIGURE 2 is a vertical sectional view taken substantially upon a plane passing along section line 22, on an enlarged scale, of FIG. 1;

FIGURE 3 is a transverse, sectional view taken substantially upon a plane passing along section line 3--3 of FIG. 2 illustrating the structural details of the upper bearing insert pads;

FIGURE 4 is a transverse, sectional view taken substantially upon a plane passing along section line 4-4 of FIG. 2 illustrating further structural details of the jack construction and specifically the operating mechanism and the lower bearing pad;

FIGURE 5 is a detailed sectional view taken substantially upon a plane passing along section line 5-5 of FIG. 1, on an enlarged scale, illustrating the structure of the self-levelling foot;

FIGURE 6 is a perspective view of one of the upper insert pads; and

FIGURE 7 is a perspective view of the lower insert pad.

Referring now specifically to the drawings, the numeral 10 generally designates the jack construction comprising the present invention which is illustrated in attached relationship to a mobile or portable shelter unit 12. Such shelter units are generally hollow parallelopiped bodies of any suitable shape and configuration and frequently, it is desired to support such shelter units in a level condition or to elevate the shelter units to a desired elevation and for this purpose each corner of the shelter unit 12 is provided with a jack construction 10 to enable the shelter unit to be levelled or elevated to a desired position.

As illustrated, an L-shaped attaching bracket generally designated by the numeral 14 is provided and which includes flanges 16 and 18 engaging around the corner of the shelter unit 12 and secured thereto in any suitable manner such as by fastening bolts 20, rivets or the like.

The flange 18 is provided with a plurality of projections or ribs 22 in longitudinally spaced relation thereon for engagement with mounting pads or flanges 24 formed on a tubular sleeve 26 with the pads or flanges 24 being secured to the flange 18 by suitable fasteners 28 such as cap screws or the like. Thus, the adapter 14 and the sleeve 26 form an attachment for the corner of a shelter unit with the sleeve 26 including a vertical bore 30 which is cylindrical in cross-section and is of substantially the same diameter throughout the length of the sleeve 26 which has suflicient length to retain an elongated cylindrical lift member 32 therein with the axis of the cylindrical lift member 32 coinciding with the axis of the cylindrical bore 30 in the sleeve 26 so that the movement of the lift member 32 will generally be in a direction perpendicular to the ground surface 34.

The elongated cylindrical member 32 is provided with an elongated rack gear 36 attached thereto. The rack gear 36 extends substantially throughout the length thereof and is secured to the lift member 32 in any suitable manner. Adjacent the upper and lower end of the rack gear 36, a bolt 38 extends therethrough with the head thereof projecting outwardly beyond the teeth on the rack gear 36 thus forming limit stops for movement of the rack gear 36 in relation to the bore 32 by virtue of the head of the bolt 38 forming a projection which will be engaged by a drive pinion gear 40 journalled on a shaft 42 in a hollow gear casing 44 attached to the sleeve 26 in diametrically opposed relation to the adapter bracket 14. Thus, as the shaft 42 is rotated and the gear thereon rotated, the rack gear 36 along with the lift member 32 will be moved longitudinally with the bolt head 28 serving as a means to limit the longitudinal movement of the rack gear 26 and correspondingly the lift member 32 in relation to the bore 30, bracket 14 and shelter unit 12.

The shaft 42 also has a pinion gear 46 mounted thereon in rigid relation ship to the pinion gear 40. Such relationship may be anchoring both gears 40 and 46 to the shaft 42 and letting the shaft 42 rotate in the casing 44 or by anchoring the shaft 42 by a setscrew 48 or by other suitable means and providing the gears 40 and 46 on a hub 50 that is journalled on the shaft 42 thus enabling the shaft 42 to remain stationary and the gears 40 and 46 and the hub rotate as a unit on the shaft 42. Meshed with the worm pinion 46 is a worm gear 52 disposed in substantially tangential relation to the upper edge of the gear 46 as illustrated in FIG. 2. The worm gear 52 is carried on the inner end of a shaft 54 journalled in a suitable bearing 56 formed on or integral with the outer wall of the casing 44 so that upon rotation of the shaft 54, the worm gear 52 and worm wheel or pinion 46 will be rotated thus raising and lowering the lift member 32.

Either attached permanently to the outer end of the shaft 54 or detachably attached thereto is an elongated operating handle 58 disposed in perpendicular laterally extending relation to the shaft 54 and the end of the handle 58 connected with the shaft 54 may be provided with a drive socket or stud detachably engaged with the shaft 54 or it may permanently attached thereto. Additionally, the operating handle 58 is preferably provided with a conventional ratchet mechanism to enable rotation of the shaft 54 to be in increments by an oscillating motion being imparted to the handle 58. The ratchet mechanism will be reversible to enable the lift member to be elevated or lowered or, if desired, a direct drive may be provided thus requiring rotation of the handle 58. However, inasmuch as the bracket assembly 14 will at sometime be close to the ground surface, the use of the ratchet mechanism is preferable.

As illustrated, the upper end of the sleeve 26 is provided with a hollow radial extension 60 and in a similar manner, the lower end of the sleeve 66 is provided with a hollow extension 62 which generally conforms with the configuration of the rack gear 36 and serves to cover a portion of the rack gear and prevent entry of foreign materials between the drive pinion gear 40 and the ra.-.k

gear 36.

Adjacent the upper end of the sleeve 26, there is provided four radially extending passages or bores 64 each of which is provided with a plug 66 in the outer end thereof and a reduced diameter portion 68 where it communicates with the bore 30. Received in each of the bores 64 are button-like elements 70 having a headed end 72 engaging the shoulder defined by the reduced inner end portion 68 of the radial passageway 64. The inner end of the button 70 projects into the bore 30 and engages the periphery of the cylindrical lift member 32 as illustrated in FIG. 3. The two buttons at the portion of the sleeve remote from the bracket assembly 44 extend into the central aperture 74 of an upper bearing pad 76 which is constructed of a non-metallic material such as plastic or the like and the buttons 70 are also constructed of a suitable plastic material. The pads 76 engage the lift member 32 over a greater surface area than the inner ends of the buttons 70 thus forming a bearing surface therefor. Inasmuch as the forces exerted by the lift member above the gear 40 are normally counteracted by the other portion of the bore 30, the bearing pad 76 will effectively form a bearing support for the outer surface of the lift member 32 during movement thereof through the sleeve 26 and thus serve to effectively prevent any possible contacting engagement between the lift member 32 and the inner surface of the bore 30. The button 70 at the inner portion of the sleeve 26 will be adequate to support the member 32 in spaced relation to the bore 30 inasmuch as the forces exerted inwardly by the lift member 32 are quite small as compared with the forces exerted outwardly thereby during the lifting operation and during the supporting operation.

At the lower end of the sleeve 26, similar arrangements of buttons are provided but on the inner surface of the lower portion of the bore 30, a semi-cylindrical bearing pad 78 is installed and is provided with a pair of spaced apertures 80 comparable to the spacing of the lower inner pair of buttons 70 whereby the buttons 70 project into the openings 80 for anchoring the bearing pad 78 in position on the inner surface of the bore 30. The bearing pad 78 is also constructed of a plastic material to serve as a bearing for the lift member 32 and in the lower portion of the sleeve 26, the major forces exerted by the lift member 32 will be in an inward direction thus enabling only a semi-cylindrical bearing pad to be employed to effectively support the lift member 32 and to prevent engagement directly with the inner surface of the bore 30.

As illustrated, the lift member 32 is preferably tubular and it as -well as the sleeve 26 is preferably constructed of an aluminum alloy to provide a lightweight constuction which is subject to severe scufiing and galling in the event of metal to metal contact during movement of the lift member 32 and the adition of the bearing pads 76 and 78 serve to effectively space the lift member 32 from the inner surface of the bore 30 even when loads are placed thereon whereas the buttons 70 serve to keep the lift member 32 spaced from the bore 30 when no load is applied thereto.

The lower end of the tubular lift member 32 is provided with a plug 82 secured in place by a diametric pin 84 or the like. The plug 82 is provided with a bore 86 receiving a cylindrical bracket 88 which is hollow in the interior thereof and through which the anchor pin 84 extends. The lower end of the plug 82 is provided with a concave recess or surface area 90 which faces downwardly and the lower end of the bracket 88 is provided with a laterally extending flange 92 engaging the concave surface 90 and the lower surface of the flange and the bracket 88 is concave as at 94.

A self-levelling foot 96 is disposed under the tubular lift member 32 and includes a depending peripheral flange 98 defining a hollow area 100. Centrally of the foot 96, there is an integral upstanding hollow projection 102 having a hollow interior 104 with the exterior surface of the upstanding projection 102 being substantially semispherical and in bearing engagement with the concave partial spherical surface 94 on the bracket 98. The central portion of the upstanding semi-spherical projection 102 is provided with an opening 106 through which extends a screwthreaded fastener bolt 108 which is threaded into the lower end of the bracket 88 and which also extends through a retaining plate 110 which has a convex upper surface conforming with and engaging the undersurface of the semi-spherical projection 102 in peripheral relation to the aperture 106 thus adjustably securing the levelling foot 96 to the lift member 32 while enabling universal movement of the levelling foot 96 within the limits of the aperture 106. Where the screwthreaded bolt or cap screw 108 is threaded into the lower end of the bracket 88, the bracket 88 is provided with a projection 112 which is also received in the aperture 106 to serve as a limit for the relative pivotal movement between the levelling foot 96 and the lift member 32 inasmuch as the projection 102 will engage the periphery of the opening 106. The bolt 108 should be tightened tight thus compressing plate 110 against the shoulder 112 on bracket 88 which limits movement of plate 110 to provide sufficient looseness whereby enabling the levelling foot 96 to pivot in any desired direction so that it will rest flat against the ground surface even though the ground surface may not be perpendicular to the longitudinal axis of the lift member 32.

The upper end of the tubular member 32 may be closed by a closure cap or plate integral therewith or secured thereto in any suitable manner to prevent entry of rain, snow or the like and also to prevent entry of foreign material therein. By constructing the device of aluminum alloys, the jack construction may be relatively light in Weight but yet suficiently rugged to lift the necessary loan encountered in shelter units of this nature. In view of the manner of mounting the jack construction on the outer wall of the shelter unit and at each corner thereof, the bearing pads receive and counteract the forces exerted by the lift member 32 and may be of any suitable material such as Teflon which does not require lubrication which frequently is not available in remote areas in which the shelter unit may be placed.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A jack construction comprising a sleeve having means thereon for connection with a load, an elongated lift member slidably received in said sleeve, means interconnecting said sleeve and lift member for moving the lift member longitudinally in relation to the sleeve, and means interposed between at least diametrically opposed and longitudinally spaced portions of the sleeve and lift member to form bearing surfaces for the lift member during movement thereof, said means forming a bearing surface including a pair of insert pads adjacent the upper end of said sleeve and disposed at one side thereof, and a semi-cylindrical insert pad adjacent the lower end of the sleeve and disposed on the side thereof diametrically opposite to the insert pads adjacent the top thereof, and inwardly projecting buttons at both the upper and lower ends of the sleeve, said buttons including an inner end projecting into the interior of the sleeve, said upper and lower pads each having at least one aperture therein receiving the inner end of a corresponding button to retain the pad in position.

2. The structure as defined in claim 1 wherein said lift member includes a levelling foot at the lower end thereof, and means connecting the levelling foot to the lower end of the lift member for limited universal pivotal movement of the levelling foot in relation to the lift member.

3. The structure as defined in claim 2 wherein said means connecting the levelling foot to the lift member includes a downwardly facing partially spherical socket in the lower end of the lift member, said levelling foot having an upwardly projecting partially spherical member in bearing engagement with the socket on the lift member, means retaining the spherical surfaces in contacting bearing engagement, said means being in the form of a fastener assembly, the spherical projection on the levelling foot having an aperture receiving the fastener assembly to enable limited universal movement thereof.

4. A jack comprising an elongated cylindrical member having a foot at the lower end thereof and a longitudinal rack gear extending along a major portion of the length thereof, a sleeve slidably receiving said lift member, means on said sleeve for engagement with a load, gear means on said sleeve in meshing engagement with the rack gear for moving the lift member in relation to the sleeve, and longitudinally spaced bearing means interposed between said sleeve and said lift member, each of said bearingmeans including an arcuate pad of nonmetallic material slidingly engaging said lift member at least at diametrically opposed peripheral portions thereof peripherally spaced laterally of the rack gear.

5. The structure as defined in claim 4 wherein said lift member is constructed of a material subject to galling when slidably contacting metal surfaces, such as aluminum, said pads being constructed of plastic material to prevent galling of the lift member.

References Cited UNITED STATES PATENTS 1,526,153 2/1925 Kinney 254-97 2,119,028 5/ 1931 Schmidt 254133 X 2,383,204 8/1945 Le Veque 25497 3,338,554 8/ 1967 Gostomski 25486 X ROBERT C. RIORDON, Primary Examiner D. R. MELTON, Assistant Examiner 

